To enhance the research capabilities of NIH-funded projects in Washington University, a state-of-the-art high frequency array-based ultrasound imaging system (i.e., Visual Sonics Vevo 2100) will be acquired and custom-built for novel photoacoustic tomography (PAT). Ultrasound imaging and PAT provide complementary contrasts;the former measures mechanical contrast and provides morphological and flow imaging, whereas the latter measures optical contrast and provides speckle-free functional and molecular imaging (e.g., total concentration and oxygen saturation of hemoglobin). Incorporating PAT into ultrasonography will not only enrich preclinical small-animal research, but also accelerate translational and clinical research by facilitating physicians'acceptance of PAT. Vevo 2100 was released at the end of 2008 and is not yet available at Washington University. High-frequency ultrasonic imaging has transformed conventional ultrasonic imaging by providing exquisite spatial and temporal resolution;this ultrasound-array-based model will supplant the older single-element-based Vevo 770. The new system, which offers further improved imaging speed and spatial resolution, can accommodate a variety of animal models, including: mouse, rat, rabbit, zebra fish, and chick embryo;reinforcing its role in multidisciplinary research areas that include oncology, cardiology, developmental biology, and drug development. PAT is one of the fastest growing biomedical imaging technologies;it permits high-resolution sensing of rich optical contrast at super-depths in vivo-depths beyond the optical transport mean free path (~1 mm in the skin). While commercially available high-resolution three-dimensional optical imaging modalities-including confocal microscopy, two-photon microscopy and optical coherence tomography-have fundamentally impacted biomedicine, none can reach super-depths in scattering biological tissue. PAT uses low ultrasonic scattering to equivalently improve tissue optical transparency by a factor of 1000 and consequently penetrates super-depths at high resolution;simultaneous optical contrast-based functional and molecular imaging has been achieved. PAT can image sub cellular organelles and organs at multiple length scales in vivo with the same contrast origin. While PAT is expected to find broad applications, multiscale PAT will likely play a critical role in multiscale biology research. PUBLIC HEALTH RELEVANCE: Advanced imaging technologies are integral to biomarker detection as well as early diagnosis of disease. Functional and molecular imaging that detects disease-specific biomarkers in the context of tissue structure will profoundly impact biomedicine. The combination of high-frequency ultrasound imaging and photoacoustic imaging will accelerate basic biomedical research and enhance clinical healthcare.